1. Field of the Invention
This invention pertains to gas instantaneous water heaters for boats or recreational vehicles.
2. Description of the Prior Art
Existing gas instantaneous water heaters are designed for use within the home or commercial building which occupy a large volume of space and generally approach 1,000 pounds or more in weight. Touching certain portions of the exterior of the instantaneous water heater, while in operation, can cause severe burning. For this reason, existing devices cannot be mounted adjacent any wall surface or flammable surface and are usually mounted in a closet or utility room to prevent children, pets, etc. from inadvertently contacting the apparatus.
Consequently, because of the size and weight of existing apparatus, a need exists for a small light weight gas instantaneous water heater for use on boats and RV vehicles. Moreover, a need exists for an instantaneous water heater which can be mounted either inside or outside the boat or vehicle. If it is mounted on the inside, it must be easily vented to the outside, yet be sufficiently insulated so as to be capable of fitting within small spaces without fear of burning the surrounding environment. Furthermore, because none of the home models are designed with such factors as small spaces and surrounding environment, they lack the necessary safety elements which must accompany a small gas instantaneous water heater.
U.S. Pat. No. 3,887,325, issued to Finger, et al., teaches an instanteous water heater for use in deicing airplanes, and more particularly to a control method and apparatus for the burners which heat the water. This apparatus does not have the same problems as the present invention in that it is designed generally for use outside in cold weather. Consequently, venting gases and heating surrounding areas are of little importance in the operation and function of this device.
U.S. Pat. No. 3,981,344, issued to Gouyon-Beauchamps discloses a safety device for instant water heaters and specifically a control system to permit venting the combustible gases into the living area of a dwelling and yet prevent dangerous levels of combustible poisonous gases from accumulating in the room. This device has safety considerations exclusively caused by operating and venting the device within the living area of a dwelling. Furthermore, the amount of air leakage into the dwelling area in which the water heater is mounted must be known to calculate the length of time the water heater can operate before critical levels of poisonous gases accumulate. Consequently, this device is non-analogous art as compared to the present invention.
U.S. Pat. No. 4,147,159 to Thorwaldson teaches the typical heavy, bulky instantaneous water heater generally employed in a home or commercial building which possesses all the above noted problems. This device, because of its size of weight and because of its uninsulated character, is not suitable for use in a boat or recreational vehicle.
U.S. Pat. No. 4,184,457 to Trotter, et al teaches a water flow responsive control for a liquid heater. This device primarily relates to the typical instantaneous water heater used in a home or commercial building, but is primarily directed toward a control capable of sensing the amount of flowing water and controlling the flow of gas based upon the amount of flowing water. As the volumetric flow rate of the water increases, the flow of gas to the heater increases, thus maintaining a constant temperature hot water output. Such an elaborate control occupies great space and is not useful in boats and recreational vehicles, and therefor this device is not pertinent to the present invention.
U.S. Pat. No. 4,346,835 to Trotter, et al discloses a gas instantaneous water control valve employing several actuators in several chambers and a gas venturi. This device, like the other Trotter, et al device, is cumbersome and bulky, and occupies vast space to be of value in a boat or recreational vehicle.
None of the above prior art references are adaptable or even useful in a boat or recreational vehicle, because of the problems inherently associated with the various devices that must be overcome. Consequently, the need exists for a small, lightweight instantaneous hot water heater capable of being mounted on a boat or recreational vehicle.